The main methods for transmission of optical signals are amplitude phase modulation or advantageously binary differential phase shift keying BDPSK. For demodulation of differential phase modulated signals what are referred to as receive arrangements are used, of which the optical outputs are routed via opto-electrical converters (photodiodes) to the differential inputs of an amplifier which outputs a demodulated electrical data signal. Although this receiver type, when compared to “unbalanced” receivers, exhibits an improved function, it is however sensitive in relation to the dispersion of the transmission fibers (Group Velocity Dispersion—GVD).